Guardian News and Media/London

Government proposals to change the system for approval of drugs that can be used in the NHS are still in a “nebulous” state and taking an unacceptably long time to be worked out, say MPs.

The government has floated ideas for what it calls “value-based pricing” of drugs, which would remove the final say on whether or not a drug could be used in the NHS away from the National Institute for Health and Clinical Excellence (Nice).

The institute has been regularly attacked for turning down new medicines on the grounds that they do too little for too much money.

This “cost-effectiveness” criteria would be replaced by a negotiation between the manufacturer and health officials once Nice has appraised the drug and agreed that it has benefit to patients.

The idea is that a price would be agreed on the basis of the “value” the drug represents to the NHS, taking into account issues such as the need of patients for the medicine and whether it is innovative or similar to another drug.

But in spite of a consultation document two years ago and publication of the response to it last July, “it remains a source of concern that so little progress has been made on defining this nebulous concept”, says the report by the Commons health select committee.

“We do not regard it as acceptable that the arrangements for value-based pricing have still not been settled and that those who will have to work with those arrangements are still unclear about what value-based pricing will mean in practice.”

Drug companies, doctors and patients all need to know how the new system will work, the MPs say, demanding that government publish details by the end of March. The committee also wants to see the detailed publication of all drug trials whether the results are positive or negative.

All the information needs to be available so that other researchers can learn for the future. “We do not believe it should be either legal or considered ethical to withhold research data about pharmaceutical products. We are therefore concerned that this simple principle is not universally applied in practice,” says the report.

It adds that MPs were also concerned by the implication of the evidence of Nice’s chief executive, Sir Andrew Dillon, who told them that Nice was having to make appraisals of drugs without having access to all relevant data.